A Year at the Shore

by Philip Henry Gosse

form have both the extremities bifid, and the points widely diverging; and some of these have the back straight, instead of curved, and these with their bifid points, look, when viewed in front, like double anchors. All are, as usual, spun out of the most brilliant glass.

Then we have in some abundance a sort[161] with firm cartilaginous walls, about one-eighth of an inch thick, standing up to the height of three-fourths, with rounded summits, running in irregular sinuations and convolutions, not unlike the cartilage of the human ear, enclosing deep hollows. The colour is opaque white, tinged with red, probably from the red mud, which is prevalent here. When cut with a knife this sponge has a sharp, crisp, gritty feel, and when a little is crushed between glass plates we distinctly hear a creaking sound. These phenomena depend on the circumstance that it is almost wholly composed of great stout three-rayed spicula, solid throughout, together with a multitude of excessively slender needles, straight, long, pointed at one end; and many others as slender, but very short; no longer, indeed, than the thickness of one of the three-rayed.[162]

Equally numerous with these, and possessing a certain amount of resemblance to them, are some thick, compact, sack-shaped masses, with angular edges and blunt points: sometimes they are flattened and dilated, like a sack when empty; sometimes rounded, like a sack when full. In the former condition several perforations occur along the terminal ridge, in the latter there is generally but one. The colour is white, slightly tinted, just as in the preceding. It stands up boldly and stiffly (or rather hangs in the natural state) from its rather narrow base to the height of about two-thirds of an inch, and the flattened specimens are as wide as this. It is nearly made up of three-rayed spicula, some of large size, but more rather small. A transverse section shows no obvious arrangement, except that of the great central channel, into which the points of the spicula project; but a longitudinal section shows the spicula built up one on another in many courses, so nearly symmetrical that hexagonal canals are formed, whose axes run transversely to the axis of the sponge; i.e., horizontally. There is very little fleshy or gelatinous matter.[163]

Again we see a showy species,[164] making soft, spongy patches of an orange or red-lead colour, an inch or more in diameter, rising into ridges a quarter of an inch high, and forming low peaks, whose apices are perforate. Its substance contains simple needles, long, nearly or quite straight, pointed at one end; these are found in great numbers in close array, the points mostly projecting from the surface. Some of them are twice as thick as others.

Now we notice another peculiar form:[165] creeping, worm-like masses of orange-yellow or buff hue, soft and spongy in texture, which throw up one or more free, erect processes, irregularly curved, an inch or more long, and about one-eighth thick on an average, but frequently swollen and contracted by turns. These are not tubular, and the tips are rounded. The general surface under a magnifier appears slightly channelled. Within we find simple needles, long, nearly straight, pointed at both ends, moderately numerous, enveloped in much yellow granular flesh.

Then there are some imposing masses of a globose form,[166] some of which attain a foot or more in diameter, though others are not more than an inch. The surface is compact and smooth, of a delicate purplish-grey hue, with a few minute orifices, each surrounded by a small paler area.

The spicula in this noble species are various: simple rods, straight, thick, long, slightly spindle-shaped, blunt at both ends, with a linear axis; three-rayed, large, stout, very unequal angled, without any central channel; a number of very small five- and six-rayed stars, the rays projecting in different planes. They are set in a dense, yellow, gelatinous flesh, in which we may at all times discover many gemmules, or eggs; the smaller (or younger) are nearly round, bristling with points in all directions like sea-urchins, changing as they grow larger to a more oval form, beset with rounded warts, instead of points. These are discharged, when mature, with the currents of water, through the orifices, and find their way to some suitable spot, where they develop themselves into the parent form.

Finally, here is a sort[167] whose colour is a pale Indian red; occurring in masses which take the form of thick, plump bands, about half-an-inch in width, but alternately swelling and contracting, which creep over the rock, meeting and uniting, and then separating, so as to leave hollow open interstices, which, however, in some specimens are gradually filled up. The swellings form pointed hillocks, the apices of which are pierced with from one to three orifices. Irregular shallow channels cover the hillocks, and converge to the apices. It contains simple needles, slender, straight (or slightly curved), pointed at each end, not very numerous, thickly invested with granular flesh. This Sponge shrivels much, and becomes shapeless in drying, but changes little in colour. It is abundant.[168]